E-Wire Environmental Press
Ground Water Clean-Up Nanoparticles
are 1,000 Times Thinner
Than Human Hair
one looks like a "keeper"
BETHLEHEM, PA., Mar. 13
-/E-Wire/ --At a size 1,000 times thinner than a
human hair, magnetic
nanoparticles are easy to overlook. But add the minute
Herculean particles to
contaminated groundwater, and they may just change
So says a
team of environmental engineers who have pioneered and tested a
technology using nanoparticles that can cleanse polluted underground
that provide drinking water to an increasingly thirsty world.
associate professor of civil and environmental engineering
University, Bethlehem, Pa., has a patent pending for his
and has licensed the technology to two environmental
companies. He also
recently received a grant from the U.S. Environmental
Protection Agency to
explore the potential for using nanoparticles to treat
"Nanoparticles have been used in chemical processing and
engineering for years, but as far as I know, we are the first to
for groundwater cleanup,'' says Zhang. "The potential of this
help improve the environment is enormous and truly has
Nanotechnology involves pumping "nanoparticles'' --
minute, magnetic, iron-
based particles so small that 100,000 would fit on
the head of a pin, into
the groundwater. With a composition that is 99.9
percent iron and less than
0.1 percent palladium, nanoparticles have a large
relative surface area and
a high rate of reactivity -- and they race through
bloodthirsty mosquitoes searching for prey.
to water or soil contaminated with carcinogenic solvents used
in dry cleaning
and industrial processes, nanoparticles remove chlorine and
solvents to harmless hydrocarbons and chlorides commonly found
in table salt.
The approach is dramatically more effective than traditional
that require water to be pumped out, treated, then
Nanoparticle technology offers the potential for significant
example, a $20-million clean-up project might cost $5 million,
and nationwide savings could be staggering when you consider that
government alone projects spending $750 billion in the next 30 years
clean up contaminated groundwater.
The method also holds promise for
reducing the impact of bioterrorist
attempts to contaminate water because
nanoparticles can reduce biological
and chemical agents quickly, according to
Zhang. For example, Lehigh
researchers say the tiny particles were tested and
found effective in
detoxifying cyanide. The technology also might offer a
safer, cheaper, and
faster way to clean up nuclear waste and Superfund
The effectiveness of the new technology was demonstrated at the Trance
recently at its Trenton N.J. manufacturing plant. Trane, a maker of
conditioning systems, has been investigating a toxic trichloroethene
plume for several years. The company put nanoparticles to work in
monitoring wells. Samples taken from the wells 12 hours after
nanoparticles had been injected showed that as much as 96 percent of the
was reduced to harmless ethylene and ethane.
"This is the first
technology that we have found that has the potential to
clean up the
thousands of sites in many industries in the U.S., where
currently nothing is
happening,'' says Chang Tai, environmental and safety
Lehigh's researchers plan to test their remediation method this year
other contaminated groundwater sites, and are exploring the use
nanoparticles to neutralize explosives and treat nuclear waste
Nanotechnology Fact Sheet
-- Scientists say much of the nation's
groundwater is already contaminated.
Over the next 30 years, the U.S.
government alone estimates it will spend
$750 billion to clean up
contaminated groundwater, or about $8,000 per
traditional "pump and treat" clean-up method requires hydraulic pumps
bring the groundwater to the surface. The contaminated water then needs
treated in a treatment vessel to meet federal drinking water
at this point can the water be discharged.
-- Nanoparticle technology treats
water "in situ," or right in the ground.
The nanoparticles are injected into
the ground and they race around
cleansing the contaminated water.
the Trane Co. manufacturing site in Trenton, N.J., water samples were
from wells 12 hours after the nanoparticles were injected, and 96
the chemical pollution was reduced to harmless gases. Prior to
that, the most
effective method produced only a 25- percent reduction.
-- Zhang and Dan
Elliott, a Ph.D. candidate who left his job as a promising
engineer to work with Zhang on the breakthrough technology,
results of their Trenton site tests in November 2001 in the
Environmental Science and Technology. Their work was also featured
Dec. 17, 2001, issue of Chemical and Engineering News.
-- The Lehigh
scientists are searching for funding to scale up their
production, as they cannot produce them fast enough for the
tests they want
-- Nanoparticle technology could work to counter terrorist attempts
contaminate drinking water supplies, as the particles can reduce
and chemical agents quickly. For example, researchers have found
nanoparticles can detoxify cyanide.
-- The tiny particles could be
useful in cleaning up nuclear waste, as
larger particles have already been
found effective in treating uranium.
Nanoparticles also are effective in
neutralizing organic solvents, which
make up the contamination in half the
nation's Superfund sites.
/CONTACT: Tracey Moran,
610-758-4573; William Johnson, 610-758-3172/
/Web Site: http://www.lehigh.edu /